For used weapons you can check out the online auction sites. I've had very good luck but it may take some time until what your looking for at a reasonable price is offered. I bought a M54 Winchester with a vintage Lyman All-American scope in weaver mounts(post and crosswire) in great restored shape a couple of years ago. It's a 250 and accuracy is great.. As for as new Ruger cataloged rifles in 250 in several models, although I find no currently manufactured models. Reminfton made the 250 in a 'clasic' which they make for 1 year and the caliber changes each year. Many older Savage, Remington, Winchester, and Ruger rifles were chambered for the 250 cartridge. It's great little round although even a 257 Roberts may be a bit easier to find....